1. Field of the Invention
The present invention relates to a printer capable of switching over the print concentration.
Such printers as electronic photograph printers, heat transfer printers, ink jet printers, etc. are widely utilized with an output unit of a computer, etc. a copier, a facsimile and so forth.
The toner, heat transfer ink ribbons, ink cartridges, etc. in the printers are consumables, and are replaced by users.
Because of the expansion of the utilization frequency of printers in recent years, there is now a demand for reducing the volume of the toners and other consumables used in order to reduce the cost (operating costs) of said consumables.
2. Description of the Related Art
A print density adjusting/designating means is installed in an electronic photograph printer, etc. so that an operator may adjust said designating means to a desired print density and adjust the print density.
If the print density is set at a low level by this print density adjusting means, the toner volume is reduced, while if the print density is set at a high level, the toner volume is increased.
This print density adjusting function is installed so as to perform a printing operation at an optimum density without adjusting the volume of toner and the like used, though the toner volume can be adjusted if necessary.
In general, the documents etc. to be printed are sometimes required to be printed in thick black ink with serious consideration given to print quality, while documents for manuscripts are sometimes readable even though the print density is thin.
For this reason, it is preferable to perform a printing operation with serious consideration given to the print quality and a printing operation with serious consideration given to the reduction of the volume of print consumables used, which involves the following problems in the prior art.
(1) The conventional print density adjusting function is inherently a fine adjustment taking into serious consideration the print quality, and has difficulty in adjusting the print to a readable print density.
(2) Because an operator's individual preference is reflected on the adjustment as the print density is adjusted by the operator, reduction of the print consumables is not very significant.
(3) Adjustment care must be taken because the operator needs to make a fine adjustment whenever so required.